Extreme luminosities in ejecta produced by intermittent outflows around rotating black holes

Abstract

Extreme sources in the Transient Universe show evidence of relativistic outflows from intermittent inner engines, such as cosmological gamma-ray bursts. They probably derive from rotating back holes interacting with surrounding matter. We show that these interactions are enhanced inversely proportional to the duty cycle in advection of magnetic flux, as may apply at high accretion rates. We demonstrate the morphology and ballistic propagation of relativistic ejecta from burst outflows by numerical simulations in relativistic magnetohydrodynamics. Applied to stellar mass black holes in core-collapse of massive stars, it provides a robust explosion mechanism as a function of total energy output. At breakout, these ejecta may produce a low-luminosity GRB. A long GRB may ensue from an additional ultra-relativistic baryon-poor inner jet from a sufficiently long-lived intermittent inner engine. The simulations demonstrate a complex geometry in mergers of successive ejecta, whose mixing and shocks provide a pathway to broadband high energy emission from magnetic reconnection and shocks.

GRB variabilities and following gravitational waves induced by gravitational instability in NDAFs

“…There might be some alternatives to account for this anticorrelation in the literature, e.g. van Putten et al (2015) argue that the interactions between rotating BHs with the surrounding matter can increase inversely proportional to duty cycle in advection of the magnetic flux. In our explanation of such a behavior, however, we approximate this characteristic timescale (tc) to be the same as the viscous time of a fragment's accretion, tν , and probe for its inverse correlation with the luminosity provided by each fragment's accretion.…”

Proposed searches for candidate sources of gravitational waves in a nearby core-collapse supernova survey

“…More generally, it can be seen by supernova features in re-brightening bumps as optical transients appearing in a number of long duration GRB afterglow emissions, by photometry [23] and, rigorously, by spectroscopy [15,38]. The aspherical explosion of core-collapse supernovae probably derives from jets within powered by rapidly rotating neutron stars or black holes [7,41,68].…”

Near-Extremal Black Holes as Initial Conditions of Long GRB Supernovae and Probes of Their Gravitational Wave Emission

“…Spin down of black holes to moderate values of a/M requires large efficiencies, e.g., from intermittency (van Putten 1999a;McKinney et al 2012;van Putten 2015)). If L j represents an opening outflow supported by horizon flux over the full hemisphere of the black hole, E j can then be a substantial fraction of E r .…”